Paperboard cartons for carrying beverage bottles must meet a number of criteria. They must be inexpensive to make and ship, easy to use, attractive and strong.
It is an advantage to be able to stamp a carton blank in a single operation. It is also helpful to be able to fold and glue the blank to make an assembled carton using a highly automated process.
A carton should be made from inexpensive material. It is preferable that only one side of the material from which the carton is manufactured require printing. Stock material finished on one side is less expensive than that finished on both sides, and it is cheaper to print on one side of the material only.
A carton should also use a small amount of raw material. It should be made from a relatively small blank, but use a high percentage of the stock material from which it is stamped.
In order to reduce shipping and storage costs, paperboard cartons have a collapsed position for storage and for shipment from the carton manufacturer to the bottler. It is preferrable that it be possible to fold a carton from its collapsed position to its expanded position easily and using automated equipment. The expanded carton is generally required to have open bottle receiving compartments for automated loading. The carton, once in its expanded position, should be resistant to collapse; it should stay open for bottle loading.
The carton often needs a handle, especially if it is used for carrying bottles.
It is important, within the constraints imposed by economy, that a carton be strong. Bottles are stored by the distributor and retailer in cartons, and may be returned to a retailer for deposit in the original carton as well. Cartons often get wet, which can reduce the strength of paperboard.
A rectangular, collapsible box is known for the storage of screws and bolts. The blank for this box is shown and described in more detail below. Neighboring pairs of four floor flaps are glued to each other and move synchronously as the box is moved between its expanded and collapsed positions. The floor flaps fold up into the box when in its collapsed position so as to be sandwiched between side wall panels of the box. The floor flaps are shaped so that when the box is folded out from the collapsed to its expanded position, two of the flaps attached to opposite side wall panels overlie the remaining pair of floor flaps. Unfortunately, the box has a tendency to fold back into its collapsed position when empty. The presence of box contents pressing down on the box floor to maintain a flat lying position reduces this tendency. The box also has top flaps, which when folded and fastened in place hold the box in its expanded position. The two overlying floor flaps may be dimensioned to largely cover the floor area of the box so that downwardly acting forces are distributed over the box floor, lending a resilience against deformation of the box shape from such forces due to box contents.
There is also known a bottle carton having a square bottom and divided into four bottle receiving compartments by upper dividers folded in from the corners of side wall panels. The blank for this carton is also shown and described in more detail below. There are four bottom flaps, neighboring pairs of which are glued together and arranged to be folded up into the carton when in its collapsed position so as to be sandwiched between side wall panels of the carton. Two of the flaps are shaped to have edges which abut when the carton is in its expanded position. This abutment helps to hold the carton when empty from folding back up into its collapsed position. Each floor flap partially overlaps one of its neighbors. This fan-like arrangement of floor flaps does not permit a pair of opposite floor flaps to be dimensioned to largely cover the floor area of the carton for distribution of downwardly acting forces, and so the bottom of this carton tends to lack strength.